#### Presentation Title

Soil Liquefaction – Centrifuge and Fluid Dynamics Modeling

#### Abstract

Soil liquefaction is a phenomenon, happens during earthquakes in loose saturated soils causing the soil to lose its strength. Thus, it is important to evaluate the residual shear strength value of liquefied soil which represents the minimum shear strength that the soil can offer after it has liquefied. It is a very important parameter for structural designers in locations which are prone to liquefaction. In past, many researchers have tried to obtain the residual shear strength values through experiments and computational modeling. In an effort to measure residual shear strength of soil, centrifuge experiments are performed to determine the residual shear strength value by measuring the force while pulling a thin metal plate through the liquefied soil. Since soil liquefaction involves flow failure, a fluid dynamics based modeling is envisioned to capture the flow behavior and model soil liquefaction. A finite volume computational fluid dynamics (CFD) based platform is used to model the coupon pulling centrifuge experiment by considering liquefied soil to be a Newtonian viscous fluid. The forces on the coupon wall are determined from the CFD simulation results and compared with the force values measured from the experiment. By comparing the force values, it is possible to determine a range of apparent viscosity for the liquefied soil and verify with other literature to validate the model. The purpose of the study is to understand whether a fluid dynamics based approach to model liquefied soil has merit.

#### Primary Faculty Mentor Name

Mandar M Dewoolkar

#### Secondary Mentor Name

Darren Lee Hitt

#### Faculty/Staff Collaborators

Dr. Scott Michael Olson (Collaborating Mentor), Jiarui Chen (Collaborating researcher)

#### Status

Graduate

#### Student College

College of Engineering and Mathematical Sciences

#### Program/Major

Civil Engineering

#### Primary Research Category

Engineering & Physical Sciences

Soil Liquefaction – Centrifuge and Fluid Dynamics Modeling

Soil liquefaction is a phenomenon, happens during earthquakes in loose saturated soils causing the soil to lose its strength. Thus, it is important to evaluate the residual shear strength value of liquefied soil which represents the minimum shear strength that the soil can offer after it has liquefied. It is a very important parameter for structural designers in locations which are prone to liquefaction. In past, many researchers have tried to obtain the residual shear strength values through experiments and computational modeling. In an effort to measure residual shear strength of soil, centrifuge experiments are performed to determine the residual shear strength value by measuring the force while pulling a thin metal plate through the liquefied soil. Since soil liquefaction involves flow failure, a fluid dynamics based modeling is envisioned to capture the flow behavior and model soil liquefaction. A finite volume computational fluid dynamics (CFD) based platform is used to model the coupon pulling centrifuge experiment by considering liquefied soil to be a Newtonian viscous fluid. The forces on the coupon wall are determined from the CFD simulation results and compared with the force values measured from the experiment. By comparing the force values, it is possible to determine a range of apparent viscosity for the liquefied soil and verify with other literature to validate the model. The purpose of the study is to understand whether a fluid dynamics based approach to model liquefied soil has merit.